Objective: Prevalence of depression in patients with chronic obstructive pulmonary disease (COPD) varies from country to country, and even across geographic regions within countries. The aim of this study was to determine the prevalence of depression and its related risk factors in patients with COPD in Qazvin, Iran.

Method: This cross-sectional study was conducted on 100 patients (34-80 years old) with COPD referred to the pulmonary diseases clinic in Qazvin, Iran, during 2014. Demographics, medical records, current symptoms, and results of lung function tests of the participants were recorded. Moreover, the pulmonary function was evaluated. COPD was categorized according to the GOLD criteria. Beck depression inventory (BDI) was completed by all the participants. Data were analyzed using independent sample t-test, Chi-square test, and linear regression analysis.

Results: Of the 100 patients with COPD, 90 were male. Mean age was 57.57 ± 14.06 years. Moreover, among the 100 patients with COPD, 75 had depression. 67% had symptoms of mild to moderate depression and only 8% had severe depressive symptoms. There was significant association between depression and independent variables of cigarette smoking (β: 0.384, P< 0.05), body mass index (BMI) (β: -0.383, P< 0.05), and FEV1 (β: -0.264, P< 0.05).

Conclusion: The prevalence of depression in the patients with COPD was high in this study. Smoking, BMI, and FEV1 were associated with depression. Effective interventions should be developed to address this clinical concern.